Brake for hoisting apparatus.



Patented lune l7, l902.

H. VGTSCH.

BRAKE FOR HOISTING APPARATUS.

(Application filed Jan.

.(No Model.)

Fig.2.

INV ENTOR-.

A TTORA/E Y.

BY'WZ/M/ WITN E55 E5 (74d UNITED STATES PATENT OFFICE.

HERMANN VGTSGH, OF ESSEN, GERMANY, ASSIGNOR TO FRIED. KRUPP, OF

' ESSEN, GERMANY.

BRAKE FOR HOlSTlNG APPARATUS.

SPECIFICATION formingpart of Letters Eatent No. 702,834, dated June 17,1902.

Application filed January 26, 1901. Serial No- 44/798. (No model.)

T0 at whom it may concern: 4

Be it known that I, HERMANN VorscH, engineer, a citizen of the GermanEmpire, residing at 21 Kettwiger Ohaussee, Essen-on-the- Ruhr, Germany,have invented certain new and useful Improvements in Brakes for HoistingApparatus, of which the following is a specification.

The present invention has reference to improvements in hoistingapparatus, and particularly to an automatic friction-brake which enablesthe load to be raised without resistance from the brake, to be held atany elevation automatically by a brake resistance corresponding to thedesired safety, and to be lowered by simply overcoming the brakeresistance by means of force applied to the crank.

The brake constructed according to the present invention isdistinguished from the brakes heretofore known by extraordinarysimplicity and compactness of construction, and has furthermore thegreat advantage that the operating parts are contained in anentirely-closed housing, and are consequently excluded from the wearcaused by smut and grit.

The new friction-brake consists, essentially, of two friction-disksmounted upon the driving-shaft so as to rotate with the same, butadapted to be moved relatively toward and from each other, and afriction-ring provided with suitable friction-surfaces, which saidfriction-ring is carried upon the peripheries of the friction-disks andis prevented from turning when the load is lowered by a detent operatingfrom one side, while the frictiondisks are pressed constantly againstthe friction-ring by a suitable spring. In consequence of thisconstruction the friction-disks carry the friction-ring along when theload is lifted; but when the load is lowered the friction-ring is heldfast by the detent and the load is braked.

The nature of the invention will best be understood when described inconnection with the accompanying drawings, in which Figure 1 representsa vertical longitudinal section of a friction-brake constructedaccording to this invention. Fig. 2 is a vertical section on the line 22, Fig. 1, part being broken away. Fig. 3 shows a sectional View of amodified construction of the frictiondisks and the friction-ring, partbeing broken away.

Similar letters of reference designate corresponding parts throughoutthe several views of the drawings.

'Referrin g to the drawings, the letter A designates a frame, to whichthe housing B of the brake is attached by bolts or other suitable means.This housing is made of two longitudinal dished parts, having suitableflanges, through which are passed bolts or screws for uniting the same.The said housing is provided with two hubs b b, in which one end of thedriving-shaft O is supported, while the other end of said shaft issupported in a suitable bearing a, formed in a part of the frame A. Thedriving-shaft is provided at one end with a square post, to which isattached a suitable crank D for turning said shaft, and the motion ofthe shaft so induced is communicated to the winding-drum (not shown)from a gear-wheel E, rigidly mounted on said shaft in the usual manner.Within the housing B are placed two friction-disks F and F, which arekeyed to the shaft 0 by means of feathers f, so that thesefriction-disks turn with the shaft, but can be moved toward and fromeach other. The circumferences of these friction-disks are made conicalor tapered and are so arranged that the apexes of the cones face eachother, while the frictional conical surfaces slope in differentdirections. Sun rounding and mounted upon the peripheries of saidfriction-disks is a friction-ring G, provided with friction-surfacesconforming to the friction-surfaces of the friction-disks. Thefriction-disk F abuts against a shoulder c, 0 formed on thedriving-shaft O, and the other friction-disk F abuts laterally againstdished or cupped springs H, which are placed loosely upon thepriving-shaft C and are acted upon by an adj usting-nut J, screwed uponthe driv- 5 ing-shaft O. The springs H serve to press the friction-diskF constantly againstthe frictionring G, and this latterrin g against thefriction disk F, so that ordinarily the three parts are coupled byfrictional contactand all turn together. The pressure of the springs Hand the pressure caused thereby between the friction-ring and thefriction-disks, which friction is to afford the necessary brakeresistance, can be adjusted according to circumstances by means of theadjusting-nut J, which is then held in its adjusted position by means ofa lock or jam nut K. To reduce the length of the apparatus as far aspossible, the adj usting-nut J is turned cylindrically externally, andtherefore serves also as a journal for the driving-shaft C in the hub12.

M is an automatic detent acting from one side upon the friction-ring Gand which is adapted to prevent the turning of the said friction-ring inthe sense of lowering and which said detent I have shown in Figs. 1 and2 in the form of awedgingdog. The friction-ring G has its peripheryprovided with a wedge-shaped groove N, and the wedging-dog is mountedupon a stud L, mounted in the casing and extending parallel with thedriving-shaft O. The wedging-dog is provided with an eccentric edge,which is made wedge-shaped or tapered and entersthe groove N of thefriction-ring in such a manner that if the friction-ring is turned inthe direction of lowering the load the increased radii of thewedging-dog cause the latter to engage with the friction-ring and tohold the same against rotation, while if the ring is turned in theopposite directionthat is, the direction of lifting the load-the dog iscarried out of and remains out of engagement with the frictionring andthe ring is free to turn.

The operation of the brake mechanism is as follows: In raising the loadthe shaft is turned by means of the crank D in the direction of arrow I,Fig. 2, and during this movement the friction-ring G turns freely withthe frictiondisks F F, as the wedging-dog M has no retarding action onthe friction-ring. The load is therefore lifted as usual without anybraking action. If the moment of the load exceeds the moment of force atthe crank or if the force is slackened or released at the crank, theload tends to run down and causes a reverse movement of themechanismthat is, a movement in the direction of arrow 11, Fig. 2. Thefirst slight reverse movement, however, of the friction-ring G causesthe friction or wedging dog to be automatically thrown into engagementwith the friction-ring and checks its motion. Since the friction-disksare coupled to the friction-ring by frictional contact induced by thepressure of the springs H, said frictiondisks are also prevented fromfurther retrograde turning so long as the moment of friction between thefriction-ring and the friction-disks balances the moment of load. To

hold the load after the release of the crank, the moment of frictionmust exceed the moment of load, and the amount of this excess willdepend on the special purpose for which the apparatus is designed orintended. When the load is to be lowered, the crank is turned backward,and consequently the frictiondisks F F turn in the stationaryfriction-ring G and the moment of friction acts as a brake. For thepurpose of lowering the load there is required, therefore, only a momentof force which is somewhat greater than the difierence between themoment of friction and the moment of load.

Of course it is to be understood that it is not absolutely necessary tohave the frictional contact-surfaces between the friction-ring and thefriction-disks made tapering or conical, as it is evident, as shown inFig. 3, that fiat surfaces could be used; also, the wedging-dog may bereplaced by another form of detentfor instance, by a ratchet-pawl.

What I claim as new is 1. The combination of two friction-disks havingrelative lateral movement,means tending to hold the disks togethercontinuously, a friction-ring surrounding the disks, and means adaptedtohold the ring against movement.

2. The combination of two friction-disks having relative lateralmovement, a spring tending to hold the disks together, a frictionringsurrounding the disks, and means adapted to hold the ring againstmovement.

3. The combination of two friction-disks having relative lateralmovement,means tending to hold the disks together continuously, afriction-ring surrounding the disks, and an eccentric wedging-dogadapted to hold the ring against movement.

4. The combination of the shaft, two friction-disks to turn in unisonupon the shaft, one of which is movable from and toward the other, twocup-shaped springs mounted upon the shaft, tending to hold the diskstogether, a friction-ring surrounding the disks, and an eccentricwedging-dog adapted to hold the ring against movement upon rotation ofthe shaft in one direction, and to release the ring upon rotation of theshaft in the reverse direction.

5. The combination with the shaft, of disks mounted thereon, afriction-ring surrounding the disks, and an eccentric wedging-dogforcing the ring into engagement with the disks.

6. The combination with the shaft, of friction-disks mounted thereon, aspring tending to force the disks together, and means adapted to beforced into engagement with the disks to act as a brake.

7. The combination of the friction-disks, a spring tending to force thedisks together, a friction-ring surrounding the disks, and an eccentricwedging-dog adapted to force'the ring into engagement with the disks.

8. The combination with a shaft of two friction-disks having cone-shapedperipheries mounted upon the shaft and movable longitudinally thereon,cup-shaped springs mountmy hand. in the presence of two subscribing edupon the shaft and tending to force the Witnesses. disks together, afriction ring surrounding the disks, and an eccentric wedging-dogHERMANN VOTSOH' 5 adapted to force the ring into engagement Witnesses:

with the disks. WILLIAM EssENWEIN,

In testimony whereof I have hereunto set P. LIEBER.

